Cysteine cathepsins are an important class of fifteen proteases with involvement in normal development and tumor progression. To better understand their contribution to these processes, the cathepsin L protease in Drosophila melanogaster was studied. In part one of this project, the role of this cathepsin in the normal development of Drosophila wings was analyzed. The GAL4/UAS-system and RNAi were used to downregulate this cathepsin in various regions of the wing and progeny were inspected for phenotypic irregularities. An abnormal phenotype of curved wings was found and hypothesized to be a result of apoptosis. Further experimentation will be required to prove this.
In part two, the role of cathepsin L in tumor metastasis was studied in Drosophila larvae. The MARCM System and Flippase/FRT- mediated homologous recombination was used to induce benign tumors in the cephalic complex, and metastatic tumors will be induced in the future. These complexes were dissected, immunostained with the cathepsin L antibody, and imaged to visualize expression patterns. Through multiple trials, the required antibody concentration was established. It was found that this cathepsin is expressed in the cephalic complex of wild type and benign tumor-containing larvae, which established a baseline for future work. From this research, CP1 has proven to play a major role in normal Drosophila wing development and is expected to be upregulated during Drosophila tumor metastasis.
Advisor(s) or Committee Chair
Ajay Srivastava, Ph.D.
Cell Biology | Developmental Biology | Genetics | Pathogenic Microbiology
Fannin, Lindsey, "Analysis of a Cathepsin Protease in Normal Development and Tumor Metastasis in Drosophila melanogaster" (2023). Mahurin Honors College Capstone Experience/Thesis Projects. Paper 1000.
Available for download on Saturday, May 16, 2026